Sheave assembly



1963 J. H. NEWHOUSE SHEAVE ASSEMBLY Filed April 14, 1967 IN VENTOR JAMESH. NEWHOUSE ATTORNEY United States Patent 3,418,861 SHEAVE ASSEMBLYJames H. Newhouse, East Leroy, Mich., assignor to Clark EquipmentCompany, a corporation of Michigan Filed Apr. 14, 1967, Ser. No. 631,0021 Claim. c1. 74-2165) ABSTRACT OF THE DISCLOSURE A dual sheave assemblyfor reeving a pair of flexible conduits in the same plane. The sheaveassembly is connected to the extendible ram of a lift upright and a pairof flexible conduits are reeved over the sheave assembly. The conduitsare fixed at one of their ends to a stationary portion of the liftupright and at the other of their ends to the upright carriage or to adevice carried by the carriage.

Background of the invention The field of art to which the inventionpertains includes machine elements and mechanisms, and more specificallypulleys and elevator mechanisms.

When a pair of conduits are mounted on an upright to extend between thestationary upright portion and the carriage, the conduits sometimes arereeved over a pair of sheaves fixed to the upright ram in side by siderelation. This arrangement, however, has the disadvantage of reducingvisibility through the upright. Consequently, it is desirable to locatethe pair of conduits in the same plane, but in order to do thisprovision must be made for the relative movement between the conduitsdue to the different radii of the arcs through which the conduits passover the sheave in order to prevent scufling and wear between theconduits. Therefore, it is a principal object of my invention to provide:a sheave assembly which permits relative movement between a pair ofconduits trained over the sheave assembly and located in a single plane.

Summary of the invention In carrying out my invention in a preferredembodiment thereof I provide a first sheave with a groove therein. Thegroove has an inner portion and an outer portion which is wider than theinner portion. Disposed in the groove is a second sheave which isrotatable relative to the first sheave.

Brief description of the drawing FIGURE 1 is a front-quarter perspectiveview of a lift truck embodying my invention,

FIGURE 2 is an elevational View on an enlarged scale of my invention,and

FIGURE 3 is a cross-sectional view of my invention.

Description of the preferred embodiment Referring to FIGURE 1, thereference numeral denotes generally an industrial lift truck which ismounted on a pair of rear dirigible wheels 12 (only one of which isshown) and a pair of front drive wheels 14 (only one of which is shown).Truck 10 includes an operators seat 16 and various controls locatedconveniently adjacent the seat, including a steering control wheel 18.Mounted at the front end of truck 10 is a conventional telescopic liftupright 20. Upright 20 includes a stationary portion 22 formed by a pairof vertically disposed inwardly facing channels 24 which are connectedby cross braces 26. Telescoped in stationary portion 22 is an innerslide 28 which is movable vertically. Movable vertically along innerslide 28 is a carriage 30. Connected to carriage 30 is a pair of chains32 which are reeved over a pair of sprockets connected to a cross armmember 34 which is 3,418,861 Patented Dec. 31, 1968 "ice fixed to thetop of the extensible portion of an extendible ram 36 that is disposedintermediate channels 24. The ends of chains 32 which are remote fromcarriage 30 are fixed to cylinder 38 of ram 36. All of the structuredescribed thus far is conventional and does not by itself form any partof the present invention.

Sometimes, fluid operated attachments are mounted on carriage 30, and someans must be provided for supplying pressurized fluid to theattachment. In this regard a valve block 40 is connected to carriage 30and is provided with suitable fluid outlet ports 42 through whichsuitable connections to the attachment may be made. A pair of fluidconduits 44 and 46 are connected at one of their ends to valve block 40,reeved over a pair of sheave assemblies 48 (only one of which can beseen) and connected at the other of their ends to cylinder 38 of ram 36and hence to :a source of pressurized fluid carried by truck 10. It willbe noted that each sheave assembly 48 is mounted for rotation on crossarms 34 outwardly of chains 32, as will be brought out in greater detailshortly.

Referring now also to FIGURES 2 and 3, one of sheave assemblies 48 isshown in greater detail. Each sheave assembly 48 includes a first sheave50 which is generally annular in shape and has an opening 52 thereininto which a bushing 54 is pressed so that sheave 50 may be mounted forrotation on a shaft 56. Sheave 50 is made up of two parts 58 and 60which are held together by a plurality of rivets, or any other suitablefastening means. Also, sheave 50 has an outer periphery 64 in which agroove 66 is formed.

Groove 66 has an inner portion in which the sides 68 are substantiallyparallel and an outer portion in which the sides 70 are further apartthan the sides 68 and are generally concave when viewed in crosssection.

Disposed in groove 66 in the inner portion thereof is a second sheave 72which is rotatable relative to sheave 50. Sheave 72 is generally annularin shape and has a shallow arcuate groove 74 in the outer peripherythereof. Sheave 72. is manufactured in one piece and placed in groove 66before the two parts 58 and 60 of sheave 50 are riveted together.

As will be noted, two fluid conduits 44 and 46 are connected to valveblock 40. Obviously, one of these conduits can serve as a supply conduitand the other as a return conduit. Where an attachment which has only asingle function is mounted on carriage 30 nothing further is requiredinsofar as fluid conduits are concerned. However, where the attachmenthas two functions which are fluid operated, such :as a rotating rollclamp which has a fluid motor for causing rotation and another fluidmotor for controlling clamping, provision must be made for connectingthe conduits 44 and 46 either to the fluid motor for controllingrotation or to the fluid motor for controlling clamping. This isaccomplished by means of a solenoid operated spool in valve block 40.The solenoid which actuates the spool in valve block 40 is energized bymeans of an electric conductor 46 which is connected at one end thereofto the solenoid incorporated in valve block 40, reeved over sheaveassembly 48 and fixed at the other end thereof to cylinder 38 of ram 36and hence connected to a switch located adjacent the operators seat.

Since electrical conductor 76 is of substantially lesser diameter thanfluid conduit 44, conductor 76 is reeved over sheave 72 while fluidconduit 44 is reeved over sheave 50 and engages sides 70 of groove 66thereof. At this point, it will be seen that conduit 44 and conductor 76both lie in the same plane, and so contribute to better visibilitythrough upright 20. Further, since sheaves 50 and 72 are free to rotaterelative to each other and conduit 44 is located away from conductor 76there is no scrubbing orwear between conduit 44 and conductor 76,although conduit 44 and conductor 76 pass over sheave assembly 48 atdifferent speeds due to the different radii of the arcs through whichthey pass over sheave assembly 48.

It will be understood that the foregoing detailed description isintended to be illustrative only, and that while only a single preferredembodiment has been described in detail that various modifications,changes and rearrangements in structure could be made without departingfrom the spirit and scope of my invention. For example, the sides ofgroove 66 could be tapered for the full length thereof. Further, whilethe preferred embodiment is shown in conjunction with two members whichare reeved over the assembly it will be clear that the assembly could bemodified so that more than two members could be reeved over it and stillbe free to move relative to one another without scrubbing or otherwisewearing on the adjacent members. Consequently, the limits of myinvention should be determined from the following appended claims.

I claim:

1. The combination comprising a shaft, a first sheave mounted forrotation on the said shaft, the said first sheave having a groove in theouter periphery thereof, the said groove having an outer portion and aninner portion, the said inner groove portion having a first pair ofspaced apart sides, the said other groove portion having a second pairof sides which are spaced further apart than the said first pair ofsides, a second sheave disposed in the said inner groove portion androtatable relative'to the said first sheave, a first flexible elongatedmember reeved over the said second sheave, and a second flexibleelongated member reeved over the said first sheave and engaging the saidsecond pair of sides so that there is a clearance between the portionsof the said elongated members which are reeved over the said sheaves.

References Cited UNITED STATES PATENTS 698,978 4/1902 Loffi 74-2303 FREDc. MATTERN, JR., Primary Examiner.

J. A. WONG, Assistant Examiner.

